src/apps/sudoku/Stack.h

   1 /* Stack - a template stack class (plus some handy methods)
   2  *
   3  * Copyright 2001-2005, Axel Dörfler, axeld@pinc-software.de.
   4  * This file may be used under the terms of the MIT License.
   5  */
   6 #ifndef KERNEL_UTIL_STACK_H
   7 #define KERNEL_UTIL_STACK_H
   8
   9
  10 #include <SupportDefs.h>
  11
  12 #include <stdlib.h>
  13
  14 template<class T> class Stack {
  15         public:
  16                 Stack()
  17                         :
  18                         fArray(NULL),
  19                         fUsed(0),
  20                         fMax(0)
  21                 {
  22                 }
  23
  24                 ~Stack()
  25                 {
  26                         free(fArray);
  27                 }
  28
  29                 bool IsEmpty() const
  30                 {
  31                         return fUsed == 0;
  32                 }
  33
  34                 void MakeEmpty()
  35                 {
  36                         // could also free the memory
  37                         fUsed = 0;
  38                 }
  39
  40                 status_t Push(T value)
  41                 {
  42                         if (fUsed >= fMax) {
  43                                 fMax += 16;
  44                                 T *newArray = (T *)realloc(fArray, fMax * sizeof(T));
  45                                 if (newArray == NULL)
  46                                         return B_NO_MEMORY;
  47
  48                                 fArray = newArray;
  49                         }
  50                         fArray[fUsed++] = value;
  51                         return B_OK;
  52                 }
  53
  54                 bool Pop(T *value)
  55                 {
  56                         if (fUsed == 0)
  57                                 return false;
  58
  59                         *value = fArray[--fUsed];
  60                         return true;
  61                 }
  62
  63                 T *Array()
  64                 {
  65                         return fArray;
  66                 }
  67
  68                 int32 CountItems() const
  69                 {
  70                         return fUsed;
  71                 }
  72
  73         private:
  74                 T               *fArray;
  75                 int32   fUsed;
  76                 int32   fMax;
  77 };
  78
  79 #endif  /* KERNEL_UTIL_STACK_H */